An investigation of trends in precious metal and copper content of RAM modules in WEEE: Implications for long term recycling potential. (February 2017)

• Record Type: Journal Article
• Authors: Charles, Rhys Gareth; Douglas, Peter; Hallin, Ingrid Liv; Matthews, Ian; Liversage, Gareth
• Is Part Of: Waste management. Volume 60(2017)
• Page Start: 505
• Page End: 520
• Publication Date: 2017-02
• Subjects: WEEE/e-waste -- Precious metals -- Recycling potential -- Value trend -- Atomic absorption spectroscopy -- PC -- RAM; AAS atomic absorption spectroscopy -- BATRRT best available treatment, recovery and recycling techniques -- CMs critical materials -- COG cut-off grade -- DDR double data rate (SDRAM) -- DRAM dynamic RAM -- DIMMs dual in-line memory modules -- EDO extended data output (RAM) -- EEE electrical and electronic equipment -- EoL end-of-life -- EPR extended producer responsibility -- FPM fast page mode (RAM) -- HWRC household waste recycling centre -- IC integrated circuit -- MFA material flow analysis -- MLCCs multi-layer ceramic capacitor -- PCB printed circuit board -- PM precious metal -- PMR material for precious metal recovery -- POM placed on the market -- SDR single data rate (SDRAM) -- SDRAM synchronous DRAM -- SIMMs single in-line memory module -- SMD surface mounted device -- WEEE waste electrical and electronic equipment; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2016.11.018
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: Au, Ag, Pd and Cu content of historic PC RAM modules were investigated. Temporal reductions in Pd content and increases in Cu content have been identified. Projections of recycling potential of future WEEE items accounting for these trends have been made. The importance of temporal compositional variations in recycling potential projections is considered. Factors affecting future WEEE recycling viability and future outlook are considered. Abstract: Precious metal (PM) and copper content of dynamic-RAM modules placed on the market during 1991–2008 has been analysed by AAS following comminution and acid digestion. Linear regression analysis of compositional data ordered according to sample chronology was used to identify historic temporal trends in module composition resulting from changes in manufacturing practices, and to project future trends for use in more accurate assessment of future recycling potential. DRAM was found to be 'high grade' waste with: stable levels of gold and silver over time; 80% reduction in palladium content during 1991–2008; and 0.23 g/module/year increase in copper content with a 75% projected increase from 2008 by 2020. The accuracy of future recycling potential projections for WEEE using current methods based on static compositional data from current devices is questionable due to likely changes in future device composition. The impact on recycling potential projections of waste laptops, smart phones, cell phones and tablets arising in Europe in 2020 resulting from a 75% increase in copper content is considered against existing projections using static compositional data. The results highlight that failing to consider temporal variations in PM content may result in significant discrepancies between projections and future recycling potential.